1. Field of the Disclosure
The present subject matter relates to vehicle suspensions and components thereof. More particularly, the present subject matter relates to leaf spring suspensions.
2. Description of Related Art
Leaf springs are commonly used as active components in vehicle suspensions. Examples of suspensions using a leaf spring are shown and described in U.S. Pat. No. 5,938,221, which is hereby incorporated herein by reference.
One of the shortcomings associated with the design of leaf spring suspensions is due to the fact that in order to lower the vertical spring rate to a desirable level, the leaf spring sometimes must be increased in length beyond the packaging constraints of the vehicle. In particular, in certain vehicles, there are limitations on the space available to accommodate the longer length spring required to achieve a lower spring rate for a given suspension.
Contributing to this shortcoming is the manner in which the leaf spring is typically secured to the vehicle axle. In particular, the leaf spring is conventionally secured to the vehicle axle in a way that produces a mechanical metal-to-metal connection between the leaf spring and the axle clamp assembly. This conventional means of connecting the leaf spring to the vehicle axle negates utilization of a section of the leaf spring, namely its spring seat, as part of the active component, giving the leaf spring a shorter effective length than its true physical length and increasing the overall spring rate of the leaf spring. In addition, this metal-to-metal connection can be a limitation of the fatigue life for the leaf spring.
Another shortcoming of known leaf spring suspensions is the manner in which a load is transmitted from an axle by the clamp group. In particular, an axle bracket is typically secured to the axle, with the leaf spring being secured to the axle bracket by an axle clamp assembly top cap and large mechanical fasteners, such as U-bolts. The load from the axle is transmitted by friction generated by the bolts, thereby requiring relatively large bolts to generate adequate clamp force. Even when such larger bolts are used, the regular application of road-generated forces through a friction clamp joint may result in bolt loosening.
Accordingly, it is desirable to overcome one or more of the foregoing shortcomings, or alternatively other shortcomings not specified herein but associated with prior leaf spring suspensions.